Warning: Before reading this blog, consider that I could be just another person looking to justify doing the things they love to do – in spite of some evidence indicating that very activity is potentially harmful to health.

About a month ago, I wrote a blogthat looked at research asking if endurance exercise is actually detrimental to your health. Over the last few weeks, I’ve given this blog and the research considerable thought. One of the first things that came to my mind was research that indicated as much as 90-percent of research is flawed. I looked at this issue in my blog “Are researchers just a bunch of manipulative liars?”

I also went back and read the research paper I referenced in last month’s blog. A couple of thoughts came to mind:

Though the research noted, “Serologic markers of cardiac damage, including cardiac troponin, creatine kinase MB, and B-typenatriuretic peptide, have been documented to increase in up to 50% of participants during and after marathon running” – I kept thinking, “What about the other 50% of the people?” If this is a genetic issue – perhaps I’m one of the lucky ones? Maybe I'm one of the "other" 50% that is not negatively affected?

I also considered the cardiac changes in mice forced to do endurance exercise via electric shock. My thought was, “Of course they would show stressful cardiac changes – they were being electrically forced to run!”

In none of the studies cited in the research paper were 100% of the people adversely affected by high intensity or long duration exercise. This leaves me to wonder about the people that were not adversely affected – did they live longer? Are their lives somehow better?

One of the athletes I coach sent me a link to a New York Times column noting that researchers believe due to our endurance capabilities as humans, we developed bigger brains. Our very existence is due to endurance exercise.

Ah ha! There – proof that endurance exercise is good.

I also read a columnabout 91-year-young Sven Wiik that was an Olympian, “was always fixated on sports” and still skis nearly every day.

Ah ha! Here’s a living example of someone immersed in sport that is an excellent, healthy 91.

Then, across my desk came researchthat Olympic medalists live an average of 2.5 years longer than the general population.

Few athletes workout longer and more intensely than Olympians and they enjoy longevity. Perhaps some this longevity is due to endurance exercise past the age of 40?

After mulling all of this around in my head for awhile, I decided that I enjoy endurance sport. I love doing long bike rides, long runs and hours of Nordic skiing. Research does interest me, but I also understand the limitations of any research on human beings. We are complicated and it is impossible to account for controlling all the variables in any research study, including genetic influences.

All things considered, I plan to continue doing the endurance sports and racing that I love to do – until the time when I no longer feel like doing those sports. I figure I’m on the earth for a limited amount of time and I plan to take personal responsibility for spending my time as I please while I’m here.

I might cut years off of my life or suffer cardiac changes that aren’t healthy.

Or, I might live to be over 100 still doing endurance sports making researchers ask “Why? How?”

How do you plan to spend your time on earth?

************************************************

Detailed off-season plans for triathlon andcycling, along with event-specific running, cycling and more triathlonplans found here.

A fellow coach, Steve Diggs, sent me the link to this research paper. Several years ago, Steve and I had a discussion about high intensity training (HIT) programs that other coaches were using, as well as repeated training for Ironman distance events. The short of the discussion is that we both had a gut feeling that there is some top limit for the volume of HIT and overall volume of endurance training where if you go over that limit, it is harmful to your health.

Now there is research that is backing up our gut feelings. Here are a few key plucks from the research paper:

· Indeed, long-term sustained vigorous aerobic exercise training such as marathon or ultramarathon running or professional cycling has been associated with as much as a 5-fold increase in the prevalence of atrial fibrillation.

The conclusion of the investigation follows:

In some individuals, long-term excessive endurance exercise training may cause adverse structural and electrical cardiac remodeling, including fibrosis and stiffening of the atria, right ventricle, and large arteries. This theoretically might provide a substrate for atrial and ventricular arrhythmias and increase cardiovascular risk. Further investigation is warranted to identify the exercise threshold for potential toxicity, screening for at-risk individuals, and ideal exercise training regimens for optimizing cardiovascular health. For now, on the basis of animal and human data, cardiovascular benefits of vigorous aerobic exercise training appear to accrue in a dose-dependent fashion up to about 1 hour daily, beyond which further exertion produces diminishing returns and may even cause adverse cardiovascular effects in some individuals.

While it currently appears the researchers are saying “some individuals” – the endurance sports and intensities that some of us do repeatedly “may not” be good for overall health.

If it turns out that anything over an hour a day is bad for you – will you give up doing the distances and intensities you love so much?

Or – will you say everyone must die of something and if doing endurance sports year after year does it, I’m okay with that? (Comments can be added on Facebook. )

Note: Find the full article here, including a video interview with the author. The short video is worth watching.

************************************************

Detailed off-season plans for triathlon and cycling, along with event-specific running, cycling and more triathlon plans found here.

ACTIVE is the leader in online event registrations from 5k running races and marathons to softball leagues and local events. ACTIVE also makes it easy to learn and prepare for all the things you love to do with expert resources, training plans and fitness calculators.